Suspensions or slurries having moderate and high particle concentrations are found in a variety of industries. As the characteristics of the suspensions influence production costs, product quality and yield, it is useful to rapidly, cost-effectively, and non-invasively characterize these suspensions.
Commercially available devices utilizing ultrasonic measurements for particle sizing typically rely on a measurement of the through-transmitted attenuation and the velocity. While effective at low solid concentrations (<10 wt %), particle-particle interactions in higher concentration slurries can complicate both the measurement and the interpretation of the data. Also, it may be difficult to tell at what point a given measurement (e.g., through-transmission attenuation) becomes unreliable. Another potential problem arises from the very small propagation paths (on the order of millimeters), found in some commercial devices, which can become clogged. Additionally, such measurements are often obtained using facing transducers, which can lead to inaccuracies from misaligned transducers.